#include<iostream>
#include<vector>
#include<queue>
#include<malloc.h>
#include <math.h>

int main()
{
  double u,k,er,n,t;
  int a,i,j;
 
   k=9.76e-4;
   a=-2100;u=1;n=2.0/k;
   for(i=1;i<=n;i++){
     j=i-1;
     t=j*k;
     u=u+k*(a*(u-cos(t))-sin(t));
   }
   er=u-cos(2);
   std::cout<<er<<std::endl;
 
}
